Predictive value of a topical dexamethasone provocative test before intravitreal triamcinolone acetonide injection

To investigate the diagnostic value of a topical dexamethasone (DXM) provocative test before intravitreal triamcinolone acetonide (IVTA) injection for a steroid response.

Eligible patients scheduled for first-time IVTA who did not have glaucoma or a history of a steroid response received DXM 0.1% drops 4 times daily over 4 weeks. After that, IVTA was given except in DXM responders with an IOP increase greater than 15 mm Hg. IOP was measured at baseline, 4 weeks after DXM treatment, at weeks 1, 2, and 4, and at months 3 and 6 after IVTA. A steroid response after the DXM test or after IVTA was defined as an IOP increase of 6 mm Hg or greater.

Thirty-six patients (36 eyes) were analyzed. The DXM test had a sensitivity of 25% (95% confidence interval [CI], 0.07-0.52), a specificity of 100% (95% CI, 0.83-1.00), a positive predictive value of 100% (95% CI, 0.40-1.00), and a negative predictive value of 62% (95% CI, 0.44-0.79) for a steroid response after IVTA. In DXM responders, the IOP increase after IVTA was 17.0+/-7.8 mm Hg versus 5.0+/-4.4 mm Hg in DXM nonresponders (P=0.005). The IOP increase after the DXM test correlated with the IOP increase after IVTA (P=0.001).

The topical DXM test had a low sensitivity, a high specificity, a high positive predictive value, and a moderate negative predictive value and may be useful to predict a steroid response after IVTA. DXM responders demonstrated high IOP increases after IVTA, and the IOP increase after the DXM test correlated with the IOP increase after IVTA. If the DXM test result is positive, risks and benefits of IVTA should be more carefully weighted.